6436640 has 72 divisors (see below), whose sum is σ = 17710812. Its totient is φ = 2204160.

The previous prime is 6436613. The next prime is 6436643. The reversal of 6436640 is 466346.

It can be written as a sum of positive squares in 2 ways, for example, as 6210064 + 226576 = 2492^2 + 476^2 .

It is not an unprimeable number, because it can be changed into a prime (6436643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7430 + ... + 8250.

Almost surely, 2^6436640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6436640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8855406).

6436640 is an abundant number, since it is smaller than the sum of its proper divisors (11274172).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6436640 is a wasteful number, since it uses less digits than its factorization.

6436640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850 (or 835 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 29.

The square root of 6436640 is about 2537.0534089766. The cubic root of 6436640 is about 186.0171872968.

The spelling of 6436640 in words is "six million, four hundred thirty-six thousand, six hundred forty".